A common complaint is that despite their best efforts, some tech workers are forced to give an expected compensation number to do a full interview at a company.
Rebuttal #1: You can just put a placeholder. e.g. put $1 for your salary expectation.
Rebuttal #2: Collect data from your network and provide a wide range. Ambiguity is your friend here, just talk about how compensation is one factor for you.
Rebuttal #3: Finally, even if you give a number you're unhappy with with, the interview is still good practice for you.
By the time you provide numbers, you ideally have done the legwork to know what to expect.
If you have to give a number, say the minimum number that is feasible for you. e.g. you need $250k TC to pay mortgage but the job's upper band is $180k)